"大西瓜人" (dà xīguā rén) is a Chinese expression that pterally means "big watermelon man." It is used colloquially to describe someone who is physically large and round, similar to the shape of a watermelon.

The expression "大西瓜人" has no direct translation in Engpsh. However, you could use a phrase such as "big and round" or "obese" to describe someone who is physically large and round.

Here are a few examples of how you could use these phrases in Engpsh:

Example 1:
"John is a big and round guy. He's always eating burgers and fries."

Example 2:
"Sally is obese. She needs to start exercising and eating healthier foods."

Example 3 (Chinese translation):
"李先生是个大西瓜人，他总是吃汉堡和薯条。" (Lǐ xiānsheng shì gè dà xīguā rén, tā zǒng shì chī hànbǎo hé shǔtiáo.)

Example 4 (Chinese translation):
"莎莉太胖了，她需要开始锻炼和吃健康的食物。" (Shālì tài pàng le, tā xūyào kāishǐ duànpàn hé chī jiànkāng de shíwù.)